Sen. Jim DeMint (R-S.C.) said today that Republican presidential frontrunner Mitt Romney doesn’t have to prove his conservative bona fides to him and hinted that it might be time for former Speaker Newt Gingrich (Ga.) and former Sen. Rick Santorum (Pa.) to consider exiting the race.

DeMint, who endorsed Romney in 2008, stopped short of backing the former Massachusetts governor in this year’s GOP primary. But in an interview following a morning closed-door meeting with Romney in Washington, D.C., DeMint said the former governor impressed him with his commitments to fiscal reform and to repealing President Barack Obama’s health care law — as well as the “urgency” the Senator said Romney expressed in his discussions about the challenges facing the country.

“I’ve always been very impressed with Mitt. I don’t question his conservative credentials. He’s, I think, been a great leader in a lot of ways. So I feel very good about him,” DeMint told reporters. “He knows we’re on the precipice; he knows some very hard decisions need to be made; he knows we need to balance our budget, and I think he knows the next four or five years could be the most difficult our country faces.”

In an earlier interview with reporters just off the Senate floor, DeMint suggested that he expects Romney to be the nominee and indicated that he hopes Gingrich and Santorum will support the governor once that becomes apparent.

“For me, I think I’d like to move on to the real problem, which is Obama, as soon we can. But these candidates have put their heart and soul, they’ve invested so much of their lives in this thing, it’s going to be their decision when they can do more good by getting out than getting in. And I don’t know when that is. They have to decide. And no one should be able to tell them they have to get out,” DeMint said. “But I just hope that at some point they’ll realize whether they can win or not and if they can’t, the best thing they can do probably is help the one that’s going to win.

“I hope we don’t drag it out to the convention,” DeMint added in the later interview. “Each of the candidates is just going to have to decide when they’ve given it a good run.” Gingrich and Santorum are vowing to take the race to the late August Republican nominating convention in Tampa, Fla., insisting they can prevent Romney from garnering the 1,144 delegates he needs to secure the nomination.

DeMint declined to discuss the specifics of the meeting, saying it was considered private. But when asked if could share in broad terms the message Romney communicated to the Members he met with today, DeMint described it this way:

“When someone asked him in simple terms: Why are you running? He said it’s to save the country. ... That’s what I needed to hear and I think everyone in the room needed to hear — [that] really our country’s at stake, and we want a president that understands that this is not a business as usual. ... I think what we got from him is a sense of urgency.”

DeMint’s remarks couldn’t have come at a better time for Romney.

His campaign was still dealing with a media firestorm emanating from comments a top aide made Wednesday that compared the campaign process to playing with an Etch-A-Sketch toy. Romney’s critics — as well as Gingrich and Santorum — used the comments to charge that the governor will abandon the conservative positions he’s staked out in the primary once he sews up the GOP nomination.

“It’s almost like an Etch-A-Sketch,” Eric Fehrnstrom said during an interview on CNN. “You can kind of shake it up and we start all over again.”

The Romney campaign said Fehrnstrom was referring to the strategic dynamics of transitioning from running in a primary to a general election campaign, but Democrats and the governor’s conservative critics pounced. DeMint said the issue did not come up in his meeting with Romney.